1764 S. ZHOU, X. SHEN AND D. A. WOLFE and max VarŽ.fxˆŽ.Ž .On 2 m Ž2m 1.. x0,1 fxˆŽ. Ž. Ž . fx OnTherefore m Ž2m 1. uniformly for any x 0,1, which P says that regression splines do not suffer from boundary effects Gasser and Miller 1984Ž. . However, we note that the variance of fxˆŽ.near the boundary of 0,1 is much larger than in the interior .